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Knowing the age structure of endangered species is important in order to contribute to future conservation studies for such species. In this context, we investigated age structure, age at sexual maturity, potential reproductive lifespan and longevity in a population of the Charnali lizard, Darevskia dryada, an endangered species from Turkey. The results show that the Charnali lizard has a longer life span than other lizards of the genus Darevskia that live in the same region. We estimated that these lizards attain their sexual maturity at the age of one or two years and the potential reproductive life span for males and females is six and five years, respectively. As in many other lizards, the Charnali lizard exhibited a low-level male-biased sexual dimorphism in terms of increased size. We believe that this study, in which prior information related to the Charnali lizard is shared, will contribute to future conservation activities for this critically endangered species.

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TERRA TYPICA. 20 km to the west from the settlement Borchka, vilajet Artvin, north-eastern Turkey. DISTRIBUTION. The main distribution range of the species occupies the northern spurs of the East-Pontic mountains in the north-east of Turkey, at least up to the vilajet Giresun in the west. A small isolated area of the distribution range is known on the western slopes of the mountain Mtirala in the vicinity of the town Batumi in the south-west of Ajaria (Georgia). CONSERVATION STATUS. As a rare species the species was included into the Red Data Book of the USSR (1984) – category 3 and the Red Data Book of IUCN with the status ENC2a.

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TERRA TYPICA. Ravine of small Charnali River in the lower reaches of the river Chorokh in the extreme south-west of Ajaria (southwestern Georgia) and the adjacent part of Turkey. DISTRIBUTION. It occurs on a limited territory in the north-eastern foothills of the Pontic range, within extreme south-west of Ajaria in Georgia and adjoining regions of north-eastern Turkey. The distribution is not sufficiently studied. CONSERVATION STATUS. The number is rather high and stable.

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All the Turkish populations studied, both those previously assigned to D. dryada (Subaşı and Yoldere villages, near Hopa) and those attributed to D. clarkorum (the largest sample studied so far, 177 specimens in total), are indistinguishable from each other and therefore must all be ascribed to the natural variability of a monotypic D. clarkorum. The Georgian specimens from the Type Locality of D. dryada (Charnaly river gorge, Chevachauri district) are clearly different, so that taxon cannot be considered a simple synonym for D. clarkorum, but as a valid taxon, although its proper status (more probably as a subspecies of D. clarkorum), is yet to be clarified. It is a highly threatened population, so studies should be done in vivo or with as low intrusiveness as possible.

Darevskia dryada is clearly larger (SVL) than any D. clarkorum studied, with strongly longer heads and pilei in adult males (and hence more teeth in dentary bone), and higher dorsalia counts. There also seem to be (but need to be studied in a larger sample) more longitudinal rows of temporal scales between tympanic and parietal plates, a tendency to have more supralabial scales; comparatively smaller values for longitudinal rows of scales on the ventral surface of the thigh between the femoral pores and the outer row of enlarged scales, and higher collaria, and circumanalia scales. Other differences in femoralia and gularia are also reflected in Darevsky & Tuniyev’s (1997) tables and should also be investigated with more Georgian specimens.

Two supposed discriminant characters, the frontonasal index and the presence of developed masseteric, are not valid. The frontonasal index does not discriminate both taxa; D dryada specimens fall inside the variation of D. clarkorum for this character. Also the presence of a developed masseteric plate is supposed to be rare if at all in D. clarkorum but always present in D. dryada; however, it appears in nearly 75% of D. clarkorum studied and in all D. dyada, so is also no longer valid for taxa discrimination.

Although very similar, D. clarkorum and D. dryada are morphologically different, and genetic studies (as the unpublished results mentioned by Fu, 1999) do not make the provenance of the specimens clear, and hence the correct identification of the supposed specimens of D. dryada used.

There are no geographical clines in D. clarkorum. However, as stated by Schmidtler et al. (2002), there is an inverse relationship between altitude and dorsalia values in D. clarkorum. Both the general differentiation between populations and the scalation (dorsalia) appear statistically correlated with the altitude and also with latitude (being both factors not strictly the same). The correlation seems to be stronger with morphology in general (multiple scalation characters and head biometry) than only with dorsalia. In the case of the general differentiation among samples, it is also significantly correlated with temperatures during the activity period (April-September) and with precipitation during incubation (July-August). As these climatic parameters of temperature and precipitation are not directly correlated with the dorsalia variation, the relation with altitude (and perhaps latitude) must be linked to some other climatic parameter not studied here, perhaps solar radiation or evapotranspiration.

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All the Turkish populations studied, both those previously assigned to D. dryada (Subaşı and Yoldere villages, near Hopa) and those attributed to D. clarkorum (the largest sample studied so far, 177 specimens in total), are indistinguishable from each other and therefore must all be ascribed to the natural variability of a monotypic D. clarkorum. The Georgian specimens from the Type Locality of D. dryada (Charnaly river gorge, Chevachauri district) are clearly different, so that taxon cannot be considered a simple synonym for D. clarkorum, but as a valid taxon, although its proper status (more probably as a subspecies of D. clarkorum), is yet to be clarified. It is a highly threatened population, so studies should be done in vivo or with as low intrusiveness as possible. Darevskia dryada is clearly larger (SVL) than any D. clarkorum studied, with strongly longer heads and pilei in adult males (and hence more teeth in dentary bone), and higher dorsalia counts. There also seem to be (but need to be studied in a larger sample) more longitudinal rows of temporal scales between tympanic and parietal plates, a tendency to have more supralabial scales; comparatively smaller values for longitudinal rows of scales on the ventral surface of the thigh between the femoral pores and the outer row of enlarged scales, and higher collaria, and circumanalia scales. Other differences in femoralia and gularia are also reflected in Darevsky & Tuniyev’s (1997) tables and should also be investigated with more Georgian specimens. Two supposed discriminant characters, the frontonasal index and the presence of developed masseteric, are not valid. The frontonasal index does not discriminate both taxa; D. dryada specimens fall inside the variation of D. clarkorum for this character. Also the presence of a developed masseteric plate is supposed to be rare if at all in D. clarkorum but always present in D. dryada; however, it appears in nearly 75% of D. clarkorum studied and in all D. dyada, so is also no longer valid for taxa discrimination. Although very similar, D. clarkorum and D. dryada are morphologically different, and genetic studies (as the unpublished results mentioned by Fu, 1999) do not make the provenance of the specimens clear, and hence the correct identification of the supposed specimens of D. dryada used. There are no geographical clines in D. clarkorum. However, as stated by Schmidtler et al. (2002), there is an inverse relationship between altitude and dorsalia values in D. clarkorum. Both the general differentiation between populations and the scalation (dorsalia) appear statistically correlated with the altitude and also with latitude (being both factors not strictly the same). The correlation seems to be stronger with morphology in general (multiple scalation characters and head biometry) than only with dorsalia. In the case of the general differentiation among samples, it is also significantly correlated with temperatures during the activity period (April-September) and with precipitation during incubation (July-August). As these climatic parameters of temperature and precipitation are not directly correlated with the dorsalia variation, the relation with altitude (and perhaps latitude) must be linked to some other climatic parameter not studied here, perhaps solar radiation or evapotranspiration.

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Ilya S. Darevsky co-described 70 taxa (three genera, 46 species, 21 subspecies) in 44 publications belonging to five orders, eight families of amphibians and reptiles during his career in herpetology. Of this number, three taxa are fossil and 57 taxa are currently considered as valid. By the regions where new taxa were discovered Southeast Asia and Western Asia (includes Caucasus and Asia Minor) dominates. The largest number of descriptions was published in the Russian Journal of Herpetology.

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The final part of a series of papers on the lizards of the Caucasus, that have been published in previous years. The paper reports on the life habits, capture and keeping in terraria of several lizards of Soviet Transcaucasia. In these respects the agamid Phrynocephalus helioscopus persi- cus and three species of the lacertid genus Eremias occuring in that area (i. e. strauchi, velox, pleskei) are discussed. Finally a !ist of all lizard species and subspecies actually known to occur in this region is given.

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In Georgia, 16 species of rock lizards of the Genus Darevskia are occuring (D. alpina, D. „armeniaca`, D. brauneri, D. caucasica, D. clarkorum, D. daghestanica, D. „dahli`, D. derjugini, D. mixta, D. nairensis, D. parvula, D. portschinskii, D. praticola, D. rudis, D. „unisexualis` and D. Valentini). Besides short presentations of the single species and hints on their distribution and habitats, also some systematic remarks are given.

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Georgia, its history and the nature are briefly described. This is supplied by a short overview of the country`s herpetological fauna, with particular attention to the especially diverse family of true lizards. At the end, brief description of our common trip to Georgia (May - Juny 2002) is given.

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Many regions of the former USSR still re- ceive little attention from Western visitors, herpetologists not excluded. For the Cau- casus Mountains this is all the more sur- prising since the area forms a zone where northern and Middle Eastern flora and fauna meet, and which is thus of considera- bly zoogeographical interest. Presently we find three larger states in the Caucasus: Georgia, Azerbaijan and Arme- nia. Turkey borders to the southwest, Iran to the southeast, and in the north it is the Russian federation. Various smaller parts claim independence. The Black Sea forms the natural western boundary, the Caspian Sea the eastern one. Herpetologically the Caucasus is historically well-known because of the work of Darev- sky and collaborators on the rock lizards (at the time still in the large genus Lacerta, now in Darevskia) and the discovery of the first case of parthenogenesis in vertebrates (DAREVSKY, 1967; DAREVSKII, 1978; DAREVSKY & KULIKOVA, 1961). Below we will concentrate on the results of our field trip to Georgia during the last two weeks of June 2003. Predictably, because of our common interest in the group, the lacertids will receive the most attention.

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A phylogenetic-comparative approach was used to assess and refine existing secondary structure models for a frequently studied region of the mitochondrial encoded large subunit (16S) rRNA in two large lizard lineages within the Scincomorpha, namely the Scincidae and the Lacertidae. Potential pairings and mutual information were analyzed to identify site interactions present within each lineage and provide consensus secondary structures. Many of the interactions proposed by previous models were supported, but several refinements were possible. The consensus structures allowed a detailed analysis of rRNA sequence evolution. Phylogenetic trees were inferred from Bayesian analyses of all sites, and the topologies used for maximum likelihood estimation of sequence evolution parameters. Assigning gamma-distributed relative rate categories to all interacting sites that were homologous between lineages revealed substantial differences between helices. In both lineages, sites within helix G2 were mostly conserved, while those within helix E18 evolved rapidly. Clear evidence of substantial site-specific rate variation (covarion-like evolution) was also detected, although this was not strongly associated with specific helices. This study, in conjunction with comparable findings on different, higher-level taxa, supports the ubiquitous nature of site-specific rate variation in this gene and justifies the incorporation of covarion models in phylogenetic inference.

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The structure and evolution of a satellite DNA family was examined in lizards from the genus Darevskia(family Lacertidae). Comparison of tandem units of repeated DNA (satDNA), CLsat, in all species from the genus Darevskiahas shown that their variability is largely explained by single-nucleotide substitutions, which form about 50 diagnostic positions underlying classification of the family into three subfamilies. Maximum differences between the subfamilies reached 25%. At this level of tandem unit divergence in the subfamilies, no cross-hybridization between them was observed (at 65°C). The individual variability within one subfamily within the species was on average 5% while the variability between species consensuses within a subfamily was 10%. The presence of highly conserved regions in all monomers and some features of their organization show that satellites of all Darevskia species belong to one satDNA family. The organization of unit sequences of satellites CLsat and Agi160 also detected by us in another lizard genus, Lacerta s. str. was compared. Similarity that was found between these satellites suggests their relatedness and common origin. A possible pathway of evolution of these two satDNA families is proposed. The distribution and content of CLsat repeat subfamilies in all species of the genus was examined by Southern hybridization. Seven species had mainly CLsatI (83 to 96%); three species, approximately equal amounts of CLsatI and CLsatIII (the admixture of CLsatII was 2–5%); and five species, a combination of all three subfamilies in highly varying proportions. Based on these results as well as on zoogeographic views on the taxonomy and phylogeny of the Darevskia species, hypotheses on the evolution of molecular-genetic relationships within this genus are advanced.

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The genetic relatedness of several bisexual and of four unisexual Lacerta saxicola complexlizards was studied, using monomer sequences of the complex-specific CLsat tandem repeats and anonymous RAPD markers. Genomes of parthenospecies were shown to include different satellite monomers. The structure of each such monomer is specific for a certain pair of bisexual species. This fact might be interpreted in favor of co-dominant inheritance of these markers in bisexual species hybridogenesis. This idea is supported by the results obtained with RAPD markers; i.e., unisexual species genomes include only the loci characteristic of certain bisexual species. At the same time, in neither case parthenospecies possess specific, autoapomorphic loci that were not present in this or that bisexual species.

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The re-examination of Lacerta clarkorum Darevsky et Vedmederja, 1977 type series as well as analysis of the recently collected new material may suggest that within the frames of Northeastern Turkey and neighboring region of Adzharistan within the Georgia, live two close allopatric species: Lacerta clarkorum proper and a new species Lacerta dryada sp. nov., whose description is made in this article. Evidence is provided on the distribution and comparative ecology of both species, their possible phylogenetic relation being discussed.

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1. Sexual dimorphism and geographical variability in signs of external morphology are revealed in the species of the studied complexes of rock lizards. The most important for their diagnosis are the features of folidosis of the head. Interspecific and intraspecific differences in morphometric features, color and pattern of the body were detected. 2. In the phylogenetic analysis, the Darevskia (caucasica) samples were divided into the group of the northern slope of the Central Caucasus (D. caucasica), the East Caucasus (D. daghestanica), the Western Caucasus (D. alpina), the northern slope of the Central and Western Caucasus (D. alpina ). Reliable identification and significant genetic differences of D. caucasica and D. daghestanica samples favor their attribution to different species. Within D. alpina two groups with high genetic differences (distances) were identified. Inside Darevskia (saxicola) two lines are described, one of which is connected with the Crimea and the Western Caucasus (D. lindholmi-D. Brauneri), and the second - with the North and West Caucasus (D. saxicola-D. Szczerbaki). 3. As a result of the nomenclatural revision, the lectotype Lacerta praticola pontica, L. saxicola brauneri, L. saxicola daghestanica, L. saxicola lindholmi, and the neotype L. saxicola; Specific locations, years and authors of the description of a number of taxa have been refined. 4. It has been established that the studied supernumerary complexes include the following valid taxa: Darevskia (praticola) - D. pontica pontica, D. pontica hungarica, D. praticola praticola, D. praticola hyrcanica, D. praticola loriensis; Darevskia (caucasica) - D. alpina, D. caucasica caucasica, D. caucasica vedenica, D. daghestanica; Darevskia (saxicola) - D. brauneri brauneri, D. brauneri myusserica, D. saxicola, D. szczerbaki, D. lindholmi. Lacerta saxicola darevskii is regarded as a minor synonym for Lacerta saxicola brauneri. 5. For the first time accurate inventories of findings (1,443 locations) and GIS maps of species arealways were compiled, reliably characterizing the features of their distribution; The structure of areals, the current trends of their changes and the factors influencing the distribution of rock lizards are revealed. It is recommended to carry out conservation measures of international and national level in order to preserve the populations of D. alpina, D. brauneri myusserica and D. szczerbaki, especially in typical territories. 6. The first and only reliable paleontological find of Darevskia sp. - Darevskia sf. brauneri from the Pleistocene site, the caves of Mezmaiskaya. A hypothesis is proposed for the formation of species of complexes, according to which the isolation of their common ancestor from a hypothetical form it is logical to associate with the Miocene and Pliocene boundaries, or with the Cimmerian century of the Pliocene, 153 and the radiation of modern species - with the Akchagylian age, corresponding to the Piacenza and Gelazian tiers. The parallel formation of several Darevskia (praticola) and Darevskia (caucasica) lines around the Greater Caucasus is assumed in the early Pliocene. At the end of the Pontian age, the primary area of ​​the ancestor of the modern forms of Darevskia (saxicola) and the subsequent formation in the Mediterranean landscapes of the Black Sea coast, along the surviving cliff, D. szczerbaki, and the cuestas of the North Caucasus - D. saxicola, could have occurred at the periphery of the Caucasian peninsula.

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Hybridization is a common evolutionary process with multiple possible outcomes. In vertebrates, interspecific hybridization has repeatedly generated parthenogenetic hybrid species. However, it is unknown whether the generation of parthenogenetic hybrids is a rare outcome of frequent hybridization between sexual species within a genus or the typical outcome of rare hybridization events. Darevskia is a genus of rock lizards with both hybrid parthenogenetic and sexual species. Using capture sequencing, we estimate phylogenetic relationships and gene flow among the sexual species, to determine how introgressive hybridization relates to the origins of parthenogenetic hybrids. We find evidence for widespread hybridization with gene flow, both between recently diverged species and deep branches. Surprisingly, we find no signal of gene flow between parental species of the parthenogenetic hybrids, suggesting that the parental pairs were either reproductively or geographically isolated early in their divergence. The generation of parthenogenetic hybrids in Darevskia is, then, a rare outcome of the total occurrence of hybridization within the genus, but the typical outcome when specific species pairs hybridize. Our results question the conventional view that parthenogenetic lineages are generated by hybridization in a window of divergence. Instead,

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Considering all costs associated to sex, sexual reproduction could be expected to be rare. However, we find sexual reproduction to be pervasive in nature, and only a reduced number of taxa are completely asexual. In fact, the variety of sex reproductive systems, mating techniques and traits, reveals that the organisms’ reproduction has been an expressive target of selection and adaptation throughout evolution. Sex is selected because it facilitates adaptation in complex and changing environments (Weismann, 1889), and this has been already shown empirically in several models. However, studies and theories developed concerning the paradox of sex will not be able to clarify the current distribution and abundance of asexual lineages in nature. The understanding of rates of origin and extinction of asexual lineages, together with the putative differential evolution rates in organisms with sexual or asexual reproduction, should be considered in the main “origin of sex” question. The model used here, the genus Darevskia, is the first true parthenogenetic vertebrate described. It is a highly speciose genus, currently including 27 species, of which seven are parthenogenetic and of hybrid origin. Only a few of the sexual species contributed for the hybridization events which originated the parthenogens clonal lineages, and these were directional: the maternal species were always Darevskia raddei or D. mixta, and the paternal always D. valentini or D. portshinskii. Using a set of microsatellite and mtDNA markers, we first start to study the role of hybridization in the origin of vertebrate parthenogens, the extent of gene flow with sexual relatives and the relation between hybridization, asexuality and polyploidy, in the context of the main theories of asexual evolution proposed to date. We focus on the D. unisexualis, D. uzzelli and D. armeniaca parthenogens and polyploid backcrosses found in sympatric locations between the parthenogens and its sexual parentals. We find that only specific parental pairs are responsible for the origin of vertebrate parthenogenesis, regardless of their phylogenetic distance. Despite the recurrent hybridization presently reported in Darevskia, asexuality originated multiple times but only in a single temporal event the past. Parthenogenetic females are capable of backcrossing with sexual males, but can only produce polyploid individuals with reduced fertility that do not contribute for gene flow between parthenogens and sexuals. The sexual reproduction machinery can be lost with time in the parthenogenetic hybrids, which are most likely the result of a post-zygotic reproductive barrier to gene flow in the speciation continuum of Darevskia sexual species. In order to reconstruct the phylogenetic inference of this group, a set of capture sequence probes were designed from a transcriptome de novo assembly. Phylogenetic inference reconstruction has been extensively used to ask several evolutionary biology questions. However, despite the exponential use of high-throughput sequencing technologies and its promising applications in phylogenetics, next generation sequencing (NGS) techniques are still far from being as widely used in this field as in other areas of evolutionary genetics. The workflow developed in this thesis has proved to be not only cost-effective, but also to produce a very high number of cross genome phylogenetically informative markers in this non-model species. Finally, taking advantage of the hundreds of cross genome markers developed, a species tree was constructed and within genus relationships evaluated. Introgression tests showed a widespread pattern of gene flow across the genus, not only recent between recently diverged clades, but also both recent and ancient gene flow between early diverging Darevskia clades. Several evidences of hybridization with gene flow between diverging clades have been found in other systems. However, such widespread patterns where introgression has happened between all major clades, and in a very high number of species pairs, are not frequently found. It is also found that gene flow is completely absent between parthenogens sexual parental pairs. In groups with sexual-parthenogenetic reproducing species, pre- or post-zygotic reproductive barriers could be more difficult to attain and hybrid asexuality can, thus, effectively create reproductive barriers between diverging sexual taxa, that were likely faced with recurrent secondary contact. The work presented in this thesis shows that only a few sexual species pairs were responsible for the origin of the parthenogens, that some species acted always as the maternal species and others always as the paternal, that the phylogenetic distances between each pair are included in a wide range interval, and that introgression is found widespread across the genus but absent between the parental pairs. Regardless of the reproduction type, this study also shows the relevance and depth of hybridization during divergence. As has been shown intensively, gene flow is common during speciation and clades divergence. However, it would be interesting to analyse other groups together and test if deep branch gene flow is found only in some exclusive groups (such as sexual-asexual genera) or if it is something more widespread. This work presented here moves Darevskia towards providing a model that can be used to understand the origin of asexuality in vertebrates. Here the basis for future studies about sex and asexuality is provided, so that a focus on the differential evolution rates genomes of both reproduction mode can be analysed.

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A maximum parsimony phylogeny of 14 Caucasian species of rock lizards, genus Ijicerta, subgenus Archaeolacerta, was constructed from mitochondrial cytochrome b and ATPase 6 partial gene sequences. Congruence analyses were carried out between the two genes. A synthesis of the data sets reveals three well supported monophyletic groups: (1) the caucasica group including (Lacerta derjugini ((Lalpina, L. clarkorum) (L. caucasica, L. daghestanica))); (2) the rudis group including (L. parvula (L. portschinskii (L. vakntini, L. rudis))); and (3) the saxicola group including (L. mixta (L. nairensis (L. saxicola, L. raddeijj). Despite the diagnosis of three groups, the placement of L. praticola as a basal taxon is uncertain, as are the relationships among the three groups. The mitochondrial DNA sequence data suggested prior hybridization between L. mixta and L. alpina and possibly between L. saxicola and L. nairensis. Lacerta raddei was resolved as a paraphyletic species on the mtDNA tree; this may result from either hybridization or random gene sorting.

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In all, 103 specimens of Clark’s lizard, Darevskia clarkorum(Darevsky and Vedmederja, 1977), from 6 localities in the eastern Black Sea region of Turkey were examined in terms of pholidosis characteristics, morphometric measurements, and color and pattern features. Kolmogorov-Smirnov testing across all populations verified sexual dimorphism in the Ortacalar and Hemflin populations, regarding transversal series of ventral plates (P < 0.05). According to the Mann-Whitney U test, 16 pholidosis characteristics showed differences among the populations (P < 0.05). For comparison of morphometric measurements, 4 morphometric indices and ratios were developed. According to the results of independent t-testing, no differences were found between males and females among the populations. One-way variance analyses based on 4 morphometric indices and ratios confirmed that head index, snout-vent length/tail length, and tail length/total body length showed differences among the populations (P < 0.05). Regarding pholidosis characteristics (except rates of the presence of a masseteric plate and contact between the rostral and internasal plate), morphometric measurements, and color and pattern features, the specimens collected from 6 different localities were similar to D. clarkorum specimens mentioned in the literature. Furthermore, the known range of the species in Turkey has been extended.

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Turkey is biogeographically diverse and consequently has a rich herpetofauna. As a result of active herpetological research, the number of species has steadily increased in recent years. I present here a new checklist of amphibian and reptile species distributed in Turkey, revising the nomenclature to reflect the latest taxonomic knowledge. In addition, information about the systematics of many species is also given. In total 35 (19.4%) amphibian and 145 (80.6%) reptile species comprise the Turkish herpetofauna. Among amphibians, 16 (45.7%) anurans and 19 urodelans (54.3%) are present. Among reptiles, 11 (7.6%) testudines, 71 (49%) saurians, 3 (2.1%) amphisbaenians and 60 (41.3%) ophidians are considered part of the herpetofauna. The endemism rate in Turkey is considered relatively high with a total of 34 species (12 amphibian species – 34.3% and 22 reptile species – 15.2%) endemic to Turkey, yielding a total herpetofaunal endemism of 18.9%. While 38 species have not been threat-assessed by the IUCN, 92 of the 180 Turkish herpetofaunal species are of Least Concern (LC), 13 are Near Threatened (NT), 10 are Vulnerable (VU), 14 are Endangered (EN), and 7 are Critically Endangered (CR). In addition, 6 species are in the DD (Data Deficient) category.

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The study of genome size variation in cells of vertebrates using the DNA flow cytometry makes it possible to precisely determine polyploid individuals, which is extremely important when studying the processes of reticulate speciation. In addition, in many groups of vertebrates, closely related species often differ in the nuclear DNA content. Therefore, the purpose of our study was to explore the variability of genome size and ploidy in populations of 29 species and subspecies of mountain lizards of the genus Darevskia, as well as their hybrids. As a result of the study, the range of variability in individuals of different ploidy (91% of diploid and 9% of triploid individuals) was established not to overlap. Among diploid species, no correlation was found between the nuclear DNA content and phylogenetic relationships, geographic coordinates, altitude, average annual temperatures and precipitation. Representatives of all studied species complexes (with the exception of D. adjarica) had approximately the same limits of variability. Two species (D. derjugini and D. saxicola) show significant intraspecific variability. Comparisons of the genome size of parthenogenetic and bisexual species generally revealed no noticeable differences between them. Studies of triploid hybrids have shown that their genome size as a whole roughly corresponds to the sum of the average size of the diploid genome of the maternal parthenogenetic species and the haploid genome of the paternal species. The variability of genome sizes within samples of triploid hybrids was on average slightly higher than in most parthenogenetic species, but some lower than in bisexual species. The paper discusses peculiarities of reticulate speciation in this group of animals.

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Aim Body size is instrumental in influencing animal physiology, morphology, ecology and evolution, as well as extinction risk. I examine several hypotheses regarding the influence of body size on lizard evolution and extinction risk, assessing whether body size influences, or is influenced by, species richness, herbivory, island dwelling and extinction risk. Location World-wide. Methods I used literature data and measurements of museum and live specimens to estimate lizard body size distributions. Results I obtained body size data for 99% of the world`s lizard species. The body size–frequency distribution is highly modal and right skewed and similar distributions characterize most lizard families and lizard assemblages across biogeographical realms. There is a strong negative correlation between mean body size within families and species richness. Herbivorous lizards are larger than omnivorous and carnivorous ones, and aquatic lizards are larger than non-aquatic species. Diurnal activity is associated with small body size. Insular lizards tend towards both extremes of the size spectrum. Extinction risk increases with body size of species for which risk has been assessed. Main conclusions Small size seems to promote fast diversification of disparate body plans. The absence of mammalian predators allows insular lizards to attain larger body sizes by means of release from predation and allows them to evolve into the top predator niche. Island living also promotes a high frequency of herbivory, which is also associated with large size. Aquatic and nocturnal lizards probably evolve large size because of thermal constraints. The association between large size and high extinction risk, however, probably reflects a bias in the species in which risk has been studied.

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Many animals display complex colour patterns that comprise several adjacent, often contrasting colour patches. Combining patches of complementary colours increases the overall conspicuousness of the complex pattern, enhancing signal detection. Therefore, selection for conspicuousness may act not only on the design of single colour patches, but also on their combination. Contrasting long- and short-wavelength colour patches are located on the ventral and lateral surfaces of many lacertid lizards. As the combination of long- and short-wavelength-based colours generates local chromatic contrast, we hypothesized that selection may favour the co-occurrence of lateral and ventral contrasting patches, resulting in complex colour patterns that maximize the overall conspicuousness of the signal. To test this hypothesis we performed a comparative phylogenetic study using a categorical colour classification based on spectral data and descriptive information on lacertid coloration collected from the literature. Our results demonstrate that conspicuous ventral (long wavelength-based) and lateral (short wavelength-based) colour patches co-occur throughout the lacertid phylogeny more often than expected by chance, especially in the subfamily Lacertini. These results suggest that selection promotes the evolution of the complex pattern rather than the acquisition of a single conspicuous colour patch, possibly due to the increased conspicuousness caused by the combination of colours with contrasting spectral properties.

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Four bisexual and two unisexual species of the lizard genus Darevskia from northeastern Anatolia were searched for intestinal parasites in adult specimens. One cestode, Nematotaenia tarentolae, and two nematode species, Spauligodon saxicolae and Strongyloides darevskyi, were found, the latest identified as a Darevskia specialist. No major differences between host species were recorded. The very low infection rates and diversity result in depauperate helminth communities for all these lacertid lizards being the lowest among the Palaearctic saurians. Patterns of these helminth communities are compared with those observed in other lacertid lizards from Anatolia and Europe.

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The Clarks’ Lizard, Darevskia clarkorum is endemic to the Caucasian biodiversity hotspot, remarkable in terms of biogeography and evolutionary history in the Palearctic Realm. The purpose of this study is to evaluate the current distribution pattern of this species as well as its possible changes under various future climate scenarios. Fieldwork was conducted in Northeastern Anatolia and the Caucasus between 2019 and 2022, and 64 occurrence records and five bioclimatic variables were analysed using Ecological Niche Modeling (ENM) software. The annual temperature range is the most important variable influencing the distribution of this lizard species. The results showed that potential habitats for the Clarks’ Lizard are wider than its present distribution. It is predicted that under current climate change scenarios, this species’ range will be much more restricted than it is now. With rising greenhouse gas levels and solar radiation rates, the range of this species is expected to shift from northern Anatolia to the Caucasus mountainous areas, and would likely shrink in future. The remaining habitats of this lizard species may be significantly impacted by climate change and humaninduced habitat modification.

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External characters of 75 specimens of the nominal taxa Darevskia clarkorum (DAREVSKY & VEDMEDERJA, 1977) and Darevskia dryada (DAREVSKY & TUNIYEV, 1997) from between westernmost Georgia and the Turkish province of Giresun and from elevations between 250 m and 1750 m a. s. 1. were investigated by univariate and multivariate analysis. The pholidosis displays mainly two groups corresponding to samples from lower (colline) and higher (mon- tane) elevations. Samples from intermediate elevations show a somewhat intermediate pho- lidosis, but are apparently closer to higher elevation samples. In general, these observations correspond with the results of DAREVSKY & TUNIYEV (1997). Based on this variation DAREVSKY & TUNIYEV (1997) separate two species, D. dryada from the colline zone, which they newly describe, and D. clarkorum, which they suppose to inhabit montane areas. However, the pholidosis of our lowland D. dryada completely falls within the variation of a large series of topotypical D. clarkorum from Cankurtaran pass (700 m). Con- sequently, we regard D. dryada to be a junior synonym of D. clarkorum. Populations from warmer lowland localities tend to a finer pholidosis with relatively higher sca- le counts than populations from the cooler high elevation localities. This kind of variation re- minds of the principle of `numerical variation of pholidosis correlated with climate` described by SCHMIDTLER (1986) from similar data-sets in green lizard species of the genus Lacerta (sensu stricto). Therefore most of the variation is supposed to be modificatory and taxonomic con- sequences are rejected at present. The rock lizard D. clarkorum occurs within the Euxinic zone with more than 1200 mm annual precipitation, from thermophilic coastal Colchian broad-leaved forest up to montane conifer forest. D. clarkorum may be associated with D. derjugini barani, D. parvula adjarica, D. rudis ssp., and Darevskia sp. The habitat spectrum of D. clarkorum seems to be narrow, if the spe- cies lives sympatrically with other rock-dwelling lizards. In such cases D. clarkorum is restric- ted to mostly shaded, moist-cool microhabitats. Without competition, however, the habitat spectrum becomes considerably broader, including even dry and rather exposed structures.

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Phenotypic evolution can cause either divergent or convergent phenotypic patterns. Even adaptation to the same environment may result in divergence of some elements of phenotype, whereas for other morphological traits it could cause phenotypic convergence. We hypothesize that at least some phenotypic characters diverge monotonically, hence they evolve irreversibly even in very closely related species, and this happens in spite of multiple convergent adaptive patterns. We studied the evolution of phenotype in 13 closely related Caucasian rock lizards (Darevskia), whose phylogenetic relationships are well known. We used head shape and the outlines of three important scales, using geometric morphometrics. We studied the association of the overall head shape, individual principal components of head shape and scale outlines with four predictors: phylogeny, habitat, sex and size. The overall head shape was not correlated with any of these predictors, whereas some principal components were correlated with habitat or phylogeny. Habitat type explained the highest fraction of variation in head shape and anal scale area. The relatedness inferred from the components of phenotype not correlated with habitat was congruent with the phylogenetic tree inferred from molecular data. Although adaptation to local environments may obscure the phylogenetic signal present in phenotype, there are components of phenotype whose evolution is irreversible

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Spatial and temporal constraints on dispersal explain the absence of species from areas with potentially suitable conditions. Previous studies have shown that post-glacial recolonization has shaped the current ranges of many species, yet it is not completely clear to what extent interspecific differences in range size depend on different dispersal rates. The inferred boundaries of glacial refugia are difficult to validate, and may bias spatial distribution models (SDMs) that consider post-glacial dispersal constraints. We predicted the current distribution of 12 Caucasian forest plants and animals, factoring in the effective geographical distance from inferred glacial refugia as an additional predictor. To infer glacial refugia, we tested the transferability of the current SDMs based on the distribution of climatic variables, and projected the most transferable ones onto two climate scenarios simulated for the Last Glacial Maximum (LGM). We then calculated least-cost distances from the inferred refugia, using elevation as a friction surface, and recalculated the current SDMs incorporating the distances as an additional variable. We compared the predictive powers of the initial with the final SDMs. The palaeoclimatic simulation that best matched the distribution of species was assumed to represent the closest fit to the true palaeoclimate. SDMs incorporating refugial distance performed significantly better for all but one studied species, and the Model for Interdisciplinary Research on Climate (MIROC) climatic simulation provided a more convincing pattern of the LGM climate than the Community Climate System Model (CCSM) simulation. Our results suggest that the projection of suitable habitat models onto past climatic conditions may yield realistic boundaries of glacial refugia, and that the current distribution of forest species in the study region is strongly associated with locations of former refugia. We inferred six major forest refugia throughout western Asia: (1) Colchis; (2) western Anatolia; (3) western Taurus; (4) the upper reaches of the Tigris River; (5) the Levant; and (6) the southern Caspian basin. The boundaries of the modelled refugia were substantially broader than the refugia boundaries inferred solely from pollen records. Thus, our method could be used to: (1) improve models of current species distributions by considering the dispersal histories of the species; and (2) validate alternative reconstructions of palaeoclimate with current distribution data.

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Knowledge on the spatial distribution of taxa is crucial for the decision-making processes in conservation and management of biodiversity that rely on precise distribution data. We present an annotated list for a total of 37 amphibian (20 caudatans and 17 anurans) and 141 reptile species (11 chelonians, 70 lizards, 3 amphisbaenians and 57 snakes) in Turkey, using both available scientific literature up to December 2020 and our own fieldwork data from 1987 to 2020. We provide a comprehensive listing of taxonomy, names, distribution and conservation status of Turkish amphibians and reptiles. The herpetofauna list will be particularly useful for establishing national conservation priorities as well as for placing Turkish fauna into phylogenetic and biogeographic contexts. We compiled information published in books, journals and various web sources and added our personal data. We projected the data in the WGS84 coordinate system and created an overlay grid with cells of 50x50 km2. The database comprises more than 500 grid cells and 11,913 records. As a result, the distribution of Turkish amphibians and reptiles has been extensively mapped with geographical information systems and a database has been created. The obtained data will be useful in planning future studies on taxonomy, ecology and conservation of Turkish amphibians and reptiles.